Led tube light with bendable circuit board

ABSTRACT

An LED tube light having LED light sources, a light tube, end cap, power supply, and an LED light bar is disclosed. LED light bar is a bendable circuit board. One end of the light tube is attached to the end cap; a power supply disposed in end cap and the LED light bar is disposed inside light tube, LED light sources are mounted on LED light bar, the LED light sources and the power supply are electrically connected. LED light bar being bendable circuit board, includes a conductive layer, electrically connected to power supply, and a dielectric layer, the two layers are stackingly arranged, dielectric layer is disposed on the conductive layer away from the LED light sources, and fixed to an inner circumferential surface of the light tube. Bendable circuit board, at two ends thereof, is not fixed to an inner circumferential surface of the light tube.

FIELD OF THE INVENTION

The present invention relates to an LED tube light, and moreparticularly to an LED tube light having a LED light bar that is abendable circuit board.

BACKGROUND OF THE INVENTION

Today LED lighting technology is rapidly replacing traditionalincandescent and fluorescent lights. Even in the tube lightingapplications, instead of being filled with inert gas and mercury asfound in fluorescent tube lights, the LED tube lights are mercury-free.Thus, it is no surprise that LED tube lights are becoming highly desiredillumination option among different available lighting systems used inhomes and workplace, which used to be dominated by traditional lightingoptions such as compact fluorescent light bulbs (CFLs) and fluorescenttube lights. Benefits of the LED tube lights include improved durabilityand longevity, and far less energy consumption, therefore, when takinginto of all factors, they would be considered as cost effective lightingoption.

There are several types of LED tube lights that are currently availableon the market today. Many of the conventional LED tube light has ahousing that use material such as an aluminum alloy combined with aplastic cover, or made of all-plastic tube construction. The lightingsources usually adopt multiple rows of assembled individual chip LEDs(single LED per chip) being welded on circuit boards, and the circuitboards are secured to the heat dissipating housing. Because this type ofaluminum alloy housing is a conductive material, thus is prone to resultin electrical shock accidents to users. In addition, the lighttransmittance of the plastic cover or the plastic tube diminish overtime due to aging, thereby reducing the overall lighting or luminousefficiency of the conventional LED tube light. Furthermore, grainyvisual appearance and other derived problems reduce the luminousefficiency, thereby reducing the overall effectiveness of the use of LEDtube light.

Referring to US patent publication no. 2014226320, as an illustrativeexample of a conventional LED tube light, the two ends of the tube arenot curved down to allow the end caps at the connecting region with thebody of the lamp tube (including a lens, which typically is made ofglass or clear plastic) requiring to have a transition region. Duringshipping or transport of the LED lamp tube, the shipping packagingsupport/bracket only makes direct contact with the end caps, thusrendering the end caps as being the only load/stress points, which caneasily lead to breakage at the transition region with the glass lens.

With regards to the conventional technology directing to glass tube ofthe LED tube lamps, LED chip on board is mounted inside the glass-tubedtube lamp by means of adhesive. The end caps are made of a plasticmaterial, and are also secured to the glass tube using adhesive, and atthe same time the end cap is electrically connected to the power supplyinside tube lamp and the LED chip on boards. This type of LED tube lampassembly technique resolves the issue relating to electrical shockscaused by the housing and poor luminous transmittance issues. But thistype of conventional tube lamp configured with the plastic end capsrequires a tedious process for performing adhesive bonding attachmentbecause the adhesive bonding process requires a significant amount oftime to perform, leading to production bottleneck or difficulties. Inaddition, manual operation or labor are required to perform suchadhesive bonding process, thus would be difficult for manufacturingoptimization using automation.

In addition, the glass tube is a fragile breakable part, thus when theglass tube is partially broken in certain portion thereof, wouldpossibly contact the internal LED chip on boards when illuminated,causing electrical shock incidents. Referring to Chinese patentpublication no. 102518972, which discloses the connection structure ofthe lamp caps and the glass tube, as shown in FIG. 1 of theaforementioned Chinese patent reference, it can be seen that the lampend cap protrudes outward at the joining location with the glass tube,which is commonly done in the conventional market place. According toconducted studies, during the shipping process of the LED tube lamps,the shipping packaging support/bracket only makes contact with the lampend caps, which make the end caps as being the only load/stress points,which can easily lead to breakage at the transition coupling regions atthe ends of the glass tube. In addition, with regards to the securemounting method of the lamp end caps and the glass tube, regardless ofwhether using hot melt adhesive or silicone adhesive, it is hard toprevent the buildup and light blockage of excess (overflown) leftoveradhesive residues, as well as having unpleasant aesthetic appearancethereof. In addition, large amount of manpower is required for cleaningoff of the excessive adhesive buildup, creating further productionbottleneck and inefficiency. As shown also from FIGS. 3 and 4 of theaforementioned Chinese patent application, the LED lighting elements andthe power supply module require to be electrically connected via wirebonding technique, and can be a problem or issue during shipping due tothe concern of breakage.

Based on the above, it can be appreciated that the LED tube lightfabricated according to the conventional assembly and fabricationmethods in mass production and shipping process can experience variousquality issues. Referring to US patent publication no. 20100103673,which discloses of an end cap substitute for sealing and inserting intothe housing. However, based on various experimentation, upon exerting aforce on the glass housing, breakages can easily occur, which lead toproduct defect and quality issues. Meanwhile, grainy visual appearancesare also often found in the aforementioned conventional LED tube light.

SUMMARY OF THE INVENTION

To solve at least one of the above problems, the present inventionprovides a LED tube light having an LED light bar, in which the LEDlight bar is a bendable circuit board.

The present invention provides an LED tube light that includes aplurality of LED light sources, a LED light bar, a light tube, at leastone end cap and at least one power supply.

The present invention provides the LED light bar to be disposed insidethe light tube, the LED light sources are mounted on the LED light bar,the LED light sources and the power supply are electrically connected bythe LED light bar.

In an embodiment of the present invention, two end caps are provided, inwhich each end cap is equipped with one power supply.

The present invention provides the chip LEDs/chip LED modules mountedand fixed on the inside wall of the glass light tube by a bondingadhesive.

In alternative embodiment, the light tube can be a plastic tube, and inseveral embodiments, the light tube is a glass tube.

The present invention provides the LED light bar being the bendablecircuit board to include a conductive layer and a dielectric layer, theLED light sources are disposed on the conductive layer and areelectrically connected to the power supply by the conductive layertherebetween, the conductive layer and the dielectric layer arestackingly arranged, the dielectric layer is disposed on a surface ofthe conductive layer which is away from the LED light sources, and isfixed to an inner circumferential surface of the light tube.Furthermore, the bendable circuit board is (the LED light bar) extendingalong a circumferential direction of the light tube, the circumferentiallength of the bendable circuit board along the inner circumferentialsurface of the light tube and the circumferential length of the innercircumferential surface of the light tube is at a ratio of 0.3 to 0.5.Moreover, the bendable circuit board can further include a circuitprotection layer, the circuit protection layer can be of one layer, andthe circuit protection layer can be disposed on an outermost layer ofthe conductive layer of the bendable circuit board. In another preferredembodiment, the bendable circuit board further includes a circuitprotection layer being of two layers respectively disposed on outermostlayers of the conductive layer and the dielectric layer of the bendablecircuit board.

In embodiments of the present invention, the bendable circuit board canbe electrically connect to the power supply by wire bonding or bysoldering, not to be fixed to an inner circumferential surface of thelight tube by forming a freely extending end portion at the two endsthereof, respectively.

The present invention provides the light tube to include a main region,(optionally) a transition region, and a plurality of rear end regions, adiameter of the rear end regions is less than a diameter of the mainregion thereof, the end cap is fittingly sleeved on the rear end regionof the light tube. The (optional) transition region is formed betweenthe main region and the rear end region. The present invention providesthe bendable circuit board to be passed through the transition region tobe electrical connected to the power supply. The present inventionprovides each of the transition regions to have a length of 1 mm to 4mm.

The present invention provides the LED tube light to further comprisinga diffusion layer and a reflective film layer, in which the diffusionlayer is disposed above the LED light sources, the light emitting fromthe LED light sources is passed through the diffusion layer and thelight tube. Furthermore, the reflective film layer is disposed on aninner circumferential surface of the light tube, and the bendablecircuit board is disposed on the reflective film layer or one side ofthe reflective film layer. A ratio of a circumferential length of thereflective film layer fixed along an inner surface of the light tube anda circumferential length of the light tube is 0.3 to 0.5.

The present invention provides another embodiment for the LED tubelight, in which the LED light bar being the bendable circuit board,includes a plurality of conductive layers and a plurality of dielectriclayers, the dielectric layers and the conductive layers are sequentiallyand staggerly stacked, respectively, on a surface of one conductivelayer that is opposite from the surface of another conductive layer thathas the LED light sources disposed thereon, the LED light sources aredisposed on an uppermost layer of the conductive layers, and areelectrically connected to the power support by the uppermost layer ofthe conductive layers.

The present invention provides a hot melt adhesive to bond together theend cap and the light tube, thus allowing for realization ofmanufacturing automation for LED tube lights.

The present invention provides the power supply for the LED tube lightmay be in the form of a singular unit, or two individual units, and thepower supply can be purchased readily from the marketplace because it isof conventional design.

The present invention provides the LED light bar to be adhesivelymounted and secured on the inner wall of the light tube, thereby havingan illumination angle of at least 330 degrees.

In a preferred embodiment, the light tube can be a transparent glasstube, or a glass tube with coated adhesive film on the inner wallsthereof.

One benefit of the LED tube light fabricated in accordance with theembodiments of present invention is that as compared to having rigidaluminum plate or FR4 board as the LED light bar, when the light tubehas been ruptured, the entire light tube is still maintaining a straighttube configuration, then the user may be under a false impression theLED tube light would remain usable and fully functional. As a result,electric shock can occur upon handling or installation thereof. On theother hand, because of added flexibility and bendability of the bendablecircuit board for the LED light bar according to embodiments of presentinvention, the problems faced by the aluminum plate, FR4 board,conventional 3-layered flexible board having inadequate flexibility andbendability are thereby solved. Due to the adopting of the flexiblesubstrate/bendable circuit board for the LED light bar of embodiments ofpresent invention, the bendable circuit board (the LED light bar)renders a ruptured or broken light tube to being not able (unable) tomaintain a straight pipe or tube configuration so as to better informthe user that the LED tube light is deemed unusable so as to avoidpotential electric shock accidents from occurring.

Another benefit of the LED tube light fabricated in accordance with theembodiments of present invention is that the bendable circuit board (LEDlight bar) having a freely extending end portion together with thesoldered connection between the output terminal of the power supply, andthe freely extending end portion can be coiled to be fittinglyaccommodating inside the light tube, so that the freely extending endportions of the bendable circuit board can be deformed in shape due tocontracting or curled up to fit inside the light tube, and when using asolder bonding technique having a pad of the power supply being ofdifferent surface to one of the surfaces of the bendable circuit boardthat is mounted with the LED light sources, a downward tension isexerted on the power supply at the connection end of the power supplyand the bendable circuit board, so that the bendable circuit board withthrough-holes configured bond pad would form a stronger and more secureelectrical connection between the bendable circuit board and the powersupply. Another benefit of the LED tube light fabricated in accordancewith the embodiments of present invention is that the bendable circuitboard allows for soldering for forming solder joints between theflexible substrate and the power supply, and the bendable circuit boardcan be used to pass through the transition region and soldering bondedto the output terminal of the power supply for providing electricalcoupling to the power supply, so as to avoid the usage of bonding wires,and improving upon the reliability thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more readily apparent to thoseordinarily skilled in the art after reviewing the following detaileddescription and accompanying drawings, in which:

FIG. 1 is a perspective view of an LED tube light according to anembodiment of the present invention.

FIG. 2 is an exploded view of a disassembled LED tube light according tothe embodiment of the present invention.

FIG. 3 is a cross-sectional partial view of a light tube of the LED tubelight of the present invention at one end region thereof.

FIG. 4 is a frontal perspective schematic view of an end cap accordingto the embodiment of the LED tube light of the present invention.

FIG. 5 is a bottom perspective view of another embodiment of the end capof the present invention, showing the inside structure thereof.

FIG. 6 is a side perspective view of a power supply of the LED tubelight according to the embodiment of the present invention.

FIG. 7 is a cross-sectional partial view of a connecting region of theend cap and the light tube of the embodiment of the present invention.

FIG. 8 is perspective illustrative schematic partial view of anall-plastic end cap and the light tube being bonded together by aninduction coil heat curing process according to another embodiment ofthe present invention.

FIG. 9 is a perspective sectional schematic partial view of theall-plastic end cap of FIG. 8 showing internal structure thereof.

FIG. 10 is a sectional partial view of the connecting region of thelight tube showing a connecting structure between the LED light bar andthe power supply.

FIG. 11 is a cross-sectional view of a bi-layered flexible substrate ofthe LED tube light of the embodiment of the present invention.

FIG. 12 is an end cross-sectional view of the light tube of the LED tubelight of a first embodiment of present invention as taken along axialdirection thereof.

FIG. 13 is an end cross-sectional view of the light tube of the LED tubelight of another embodiment of present invention as taken along axialdirection thereof.

FIG. 14 is an end cross-sectional view of the light tube of the LED tubelight of yet another embodiment of present invention as taken alongaxial direction thereof.

FIG. 15 is a perspective view of an LED leadframe for the LED lightsources of the LED tube light of the embodiment of the presentinvention.

FIG. 16 is an exploded partial perspective view of the insulatingtubular part of the end cap according to another embodiment of thepresent invention, showing a supporting portion and a protruding portiondisposed on the inner surface thereof.

FIG. 17 is a cross-sectional view of the insulating tubular part and themagnetic metal member of the end cap of FIG. 16 taken along a line X-X.

FIG. 18 is a top sectional view of the end cap shown in FIG. 16, showingthe insulating tubular part and the light tube extending along a radialaxis of the light tube.

FIG. 19 is a schematic diagram showing the structure of the magneticmetal member including at least one hole, upon flattening out themagnetic metal member to be extending in a horizontal plane.

FIG. 20 is a schematic diagram showing the structure of the magneticmetal member including at least one embossed structure, upon flatteningout the magnetic metal member to be extending in a horizontal plane.

FIG. 21 is a top cross-sectional view of another preferred embodiment ofthe end cap according to the present invention, showing an insulatingtubular part in an elliptical or oval shape extending along a radialaxis of the light tube which also has a corresponding elliptical or ovalshape.

FIG. 22 is an end cross-sectional view of the light tube of the LED tubelight of another embodiment of present invention having a reflectivefilm layer disposed on one side of the LED light bar as taken alongaxial direction of the light tube.

FIG. 23 is an end cross-sectional view of the light tube of the LED tubelight of yet another embodiment of present invention having a reflectivefilm layer disposed under the LED light bar as taken along axialdirection of the light tube.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described more specifically withreference to the following embodiments. It is to be noted that thefollowing descriptions of preferred embodiments of this invention arepresented herein for purpose of illustration and description only. It isnot intended to be exhaustive or to be limited to the precise formdisclosed.

According to an embodiment of present invention, an LED tube light isshown in FIGS. 1 and 2, in which the LED tube light includes at least alight tube 1, an LED light bar 2, and two end caps 3. The LED light bar2 is disposed inside the light tube 1 when assembled. The two end caps 3are disposed at the two ends of the light tube, respectively. The lighttube 1 can be made of plastic or glass.

In the present embodiment, the light tube 1 is made of tempered glass.The method for strengthening or tempering of glass tube can be done by achemical tempering method or a physical tempering method for furtherprocessing on the glass light tube 1. For example, the chemicaltempering method is to use other alkali metal ions to exchange with theNa ions or K ions to be exchanged. Other alkali metal ions and thesodium (Na) ions or potassium (K) ions on the glass surface areexchanged, in which an ion exchange layer is formed on the glasssurface. When cooled to room temperature, the glass is then undertension on the inside, while under compression on the outside thereof,so as to achieve the purpose of increased strength, including but notlimited to the following glass tempering methods: high temperature typeion exchange method, the low temperature type ion exchange method,dealkalization, surface crystallization, sodium silicate strengtheningmethod. High-temperature ion exchange method includes the followingsteps. First, glass containing sodium oxide (Na₂O) or potassium oxide(K₂O) in the temperature range of the softening point and glasstransition point are inserted into molten salt of lithium, so that theNa ions in the glass are exchanged for Li ions in the molten salt.Later, the glass is then cooled to room temperature, since the surfacelayer containing Li ions has different expansion coefficient withrespect to the inner layer containing Na ions or K ions, thus thesurface produces residual stress and is reinforced. Meanwhile, the glasscontaining AL₂O₃, TiO₂ and other components, by performing ion exchange,can produce glass crystals of extremely low coefficient of expansion.The crystallized glass surface after cooling produces significant amountof pressure, up to 700 MPa, which can enhance the strength of glass.Low-temperature ion exchange method includes the following steps: First,a monovalent cation (e.g., K ions) undergoes ion exchange with thealkali ions (e.g. Na ion) on the surface layer at a temperature rangethat is lower than the strain point temperature, so as to allow the Kions penetrating the surface. For example, for manufacturing aNa₂O+CaO+SiO₂ system glass, the glass can be impregnated for ten hoursat more than four hundred degrees in the molten salt. The lowtemperature ion exchange method can easily obtain glass of higherstrength, and the processing method is simple, does not damage thetransparent nature of the glass surface, and not undergo shapedistortion. Dealkalization includes of treating glass using platinum(Pt) catalyst along with sulfurous acid gas and water in a hightemperature atmosphere. The Na+ ions are migrated out and bleed from theglass surface to be reacted with the Pt catalyst, so that whereby thesurface layer becomes a SiO₂ enriched layer, which results in being alow expansion glass and produces compressive stress upon cooling.Surface crystallization method and the high temperature type ionexchange method are different, but only the surface layer is treated byheat treatment to form low expansion coefficient microcrystals on theglass surface, thus reinforcing the glass. Sodium silicate glassstrengthening method is a tempering method using sodium silicate (waterglass) in water solution at 100 degrees Celsius and several atmospheresof pressure treatment, where a stronger/higher strength glass surfacethat is harder to scratch is thereby produced. The above glass temperingmethods described including physical tempering methods and chemicaltempering methods, in which various combinations of different temperingmethods can also be combined together.

In the illustrated embodiment as shown in FIG. 3, the light tube 1includes a main region 102, a plurality of rear end regions 101, and aplurality of transition regions 103. The light tube 1 is fabricated byundergoing a glass shaping process so as to form one or more narrowlycurved end regions at one or more ends thereof, in which each narrowlycurved end region includes one rear end region 101 and one transitionregion 103, from a cylindrical raw light tube. At the same time, theglass shaping process coincides to be substantially concurrently or issame as a glass toughening or tempering treatment process. In otherwords, while the light tube 1 is toughened or tempered, the narrowlycurved end regions as shown in FIG. 3 are also shaped alongside at thesame time. Each transition region 103 is located between an end of themain region 102 and one rear end region 101. The rear end region 101 isconnected to one end of the transition region 103, and the other end ofthe transition region 103 is connected to one end of the main region102. In the illustrated embodiment, the number of the rear end regions101 and the number of the transition regions 103 are two, respectively.The transition region 103 is curved or arc-shaped at both ends thereofunder cross-sectional view. As illustrated in FIGS. 7 and 9, one end cap3 is sleeved over the rear end region 101. The outer diameter of therear end region 101 is less than the outer diameter of the main region102. After undergone a glass toughening or tempering treatment process,the rear end regions 101 of the light tube 1 are formed to be aplurality of toughened glass structural portions. The end cap 3 issleeved over the rear end region 101 (which is a toughened glassstructural portion). The outer diameter of the end cap 3 is the same asthe outer diameter of the main region 102 of the light tube 1.

Referring to FIGS. 4 and 5, each end cap 3 includes a plurality ofhollow conductive pins 301, an insulating tubular part 302 and a thermalconductive ring 303. The thermal conductive ring 303 can be a metal ringthat is tubular in shape. The thermal conductive ring 303 is sleevedover the insulating tubular part 302. The hollow conductive pins 301 aredisposed on the insulating tubular part 302. As shown in FIG. 7, one endof the thermal conductive ring 303 is protruded away from the insulatingtubular part 302 of the end cap 3 towards one end of the light tube 1,of which is bonded and adhered using a hot melt adhesive 6. Asillustrated, the hot melt adhesive 6 forms a pool and then solidifies tofittingly join together the rear end region 101 and a portion of thetransition region 103 of the light tube 1 to a portion of the thermalconductive ring 303 and a portion of the insulating tubular part 302 ofthe end cap 3. As a result, the end cap 3 is then joined to one end ofthe light tube 1 using the hot melt adhesive 6. The thermal conductivering 303 of the end cap 3 is extending to the transition region 103 ofthe light tube 1. The outer diameter of the thermal conductive ring 303is substantially the same as the outer diameter of the main region 102of the light tube 1, and the outer diameter of the thermal conductivering 303 is also substantially the same as the outer diameter of theinsulating tubular part 302. The insulating tubular part 302 facingtoward the light tube 1 and the transition region 103 has a gaptherebetween. As a result, the LED tube light has a substantiallyuniform exterior diameter from end to end thereof. Because of thesubstantially uniform exterior diameter of the LED tube light, the LEDtube light has a uniformly distributed stress point locations coveringthe entire span of the LED tube light (in contrast with conventional LEDtube lights which have different diameters between the end caps 3 andthe light tube 1, and often utilizes packaging that only contacts theend caps 3 (of larger diameter), but not the light tube 1 of reduceddiameter). Therefore, the packaging design configured for shipping ofthe light tube 1 of the embodiment of present invention can include moreevenly distributed contact stress points at many more locations coveringthe entire span of the LED tube light, up to contacting along the entireouter surface of the LED tube light 1.

In the present embodiment, the outer diameter of the end caps 3 are thesame as the outer diameter of the main region 102, and the tolerance forthe outer diameter measurements thereof are preferred to be within+/−0.2 millimeter (mm), and should not exceed+/−1.0 millimeter(mm). Theouter diameter difference between the rear end region 101 and the mainregion 102 can be 1 mm to 10 mm for typical product applications.Meanwhile, for preferred embodiment, the outer diameter differencebetween the rear end region 101 and the main region 102 can be 2 mm to 7mm. The length of the transition region 103 is from 1 mm to 4 mm. Uponexperimentation, it was found that when the length of the transitionregion 103 is either less than 1 mm or more than 4 mm, problems wouldarise due to insufficient strength or reduction in light illuminationsurface of the light tube. In alternative embodiment, the transitionregion 103 can be without curve or arc in shape. Upon adopting the T8standard lamp format as an example, the outer diameter of the rear endregion 101 is configured between 20.9 mm to 23 mm. Meanwhile, if theouter diameter of the rear end region 101 is less than 20.9 mm, theinner diameter of the rear end region 101 would be too small, thusrendering inability of the power supply to be fittingly inserted intothe light tube 1. The outer diameter of the main region 102 ispreferably configured to be between 25 mm to 28 mm.

Referring to FIG. 2, the LED light bar 2 of the embodiment of thepresent invention has a plurality of LED light sources 202 mountedthereon. The end cap 3 has a power supply 5 installed therein. The LEDlight sources 202 and the power supply 5 are electrically connected bythe LED light bar 2. The power supply 5 may be in the form of a singleindividual unit (i.e., all of the power supply components are integratedinto one module unit), and to be installed in one end cap 3.Alternatively, the power supply 5 may be divided into two separate units(i.e. all of the power supply components are divided into two parts)which are installed at the end caps 3, respectively. The number of unitsof the power supply 5 is corresponding to the number of the ends of thelight tube 1 which had undergone glass tempering and strengtheningprocess. In addition, the location of the power supply is alsocorresponding to the location of the light tube 1 which had undergoneglass tempering. The power supply can be fabricated by encapsulationmolding by using a high thermal conductivity silica gel (with thermalconductivity ≧0.7 w/m·k), or fabricated in the form of exposed powersupply electronic components that are packaged by conventional heatshrink sleeved to be placed into the end cap 3. Referring to FIG. 2 andFIGS. 4-6, the power supply 5 includes a male plug 501 and a metal pin502. The male plug 501 and the metal pin 502 are located at oppositeends of the power supply 5. The LED light bar 2 is configured with afemale plug 201 at an end thereof. The end cap 3 is configured with ahollow conductive pin 301 used for coupling with an external powersource. The male plugs 501 of the power supply 5 are fittingly engagedinto the female plug 201 of the LED light bar 2, while the metal pins502 of the power supply 5 are fittingly engaged into the hollowconductive pins 301 of the end cap 3. Upon inserting the metal pin 502into the hollow conductive pin 301, a punching action is providedagainst the hollow conductive pin 31 using an external punching tool tocreate a slight amount of shape deformation of the hollow conductive pin301, thereby securing and fixing the metal pin 502 of the power supply5. Upon being energized or powered on, the electrical current passesthrough the hollow conductive pin 301, the metal pin 502, the male plug501, and the female plug 201, to reach the LED light bar 2, and throughthe LED light bar 2 to reach the LED light sources 202. In otherembodiments, the male plug 501 and the female plug 502 connectionstructure may not be employed, and conventional wire bonding techniquescan be adopted for replacement.

Referring to FIGS. 4-5 and FIGS. 7-9, the end cap 3 is sleeved over thelight tube 1. To be more specific, the end cap 3 is sleeved over therear end region 101 and extending toward the transition region 103 so asto be partially overlapping with the transition region 103. In thepresent embodiment, the thermal conductive ring 303 of the end cap 3 isextended to reach the transition region 103 of the light tube 1, an endof the insulating tubular part 302 facing the light tube 1 is notextended to reach the transition region 103, that is to say, the end ofthe insulating tubular part 302 facing the light tube 1 and thetransition region 103 has a gap therebetween, In addition, theinsulating tubular part 302 is made of a material that is not a goodelectrical conductor, but is not limited to being plastic or ceramicmaterials.

The hot melt adhesive 6 (includes a so-called commonly known as “weldmud powder”) includes phenolic resin 2127, shellac, rosin, calciumcarbonate powder, zinc oxide, and ethanol, etc. The light tube 1 at therear end region 101 and the transition region 103 (as shown in FIG. 7)is coated by the hot melt adhesive, which when undergone heating, wouldbe greatly expanded, so as to allow tighter and closer contact betweenthe end cap 3 and the light tube 1, thus allowing for realization ofmanufacturing automation for LED tube light. Furthermore, the hot meltadhesive 6 would not be afraid of decreased reliability when operatingunder elevated temperature conditions by the power supply and other heatgenerating components. In addition, the hot melt adhesive 6 can preventthe deterioration of bond strength over time between the light tube 1and the end cap 3, thereby improving long term reliability.Specifically, the hot melt adhesive 6 is filled in between an innersurface portion of the extending portion of the thermal conductive ring303 and the outer peripheral surface of the light tube 1 at the rear endregion 101 and the transition region 103 (location is shown in abroken/dashed line identified as “B” in FIG. 7, also referred to as “afirst location”). The coating thickness of the hot melt adhesive 6 canbe 0.2 mm to 0.5 mm. After curing, the hot melt adhesive 6 expands andcontacts with the light tube 1, thus fixing the end cap 3 to the lighttube 1. Thus, upon filling and curing of the hot melt adhesive 6, thethermal conductive ring 303 is bonded or fixedly arranged to an outer(circumferential) surface of the light tube 1 by the hot melt adhesive 6therebetween at the dashed line B in FIG. 7, which can also be referredto as the first location herein. Due to the difference in height betweenthe outer surface of the rear end region 101 and the outer surface ofthe main region 102, thus avoiding overflow or spillover of the hot meltadhesive 6 to the main region 102 of the light tube 1, forsaking oravoiding having to perform manual adhesive wipe off or clean off, thusimproving LED tube light production efficiency. Meanwhile, likewise forthe embodiment shown in FIG. 9, a magnetic metal member 9 is fixedlyarranged or disposed on an inner circumferential surface of theinsulating tubular part 302, and bonded to an outer peripheral surfaceof the light tube 1 using the hot melt adhesive 6, in which the hot meltadhesive 6 does not spillover through the gap between the end cap andone of the transition regions 103 during the filling process of the hotmelt adhesive 6. During fabrication process of the LED tube light, athermal generating equipment is used to heat up the thermal conductivering 303, and also heat up the hot melt adhesive 6, to thereby melt andexpand thereof to securely attach and bond the end cap 3 to the lighttube 1.

In the present embodiment, the insulating tubular part 302 of the endcap 3 includes a first tubular part 302 a and a second tubular part 302b. The first tubular part 302 a and the second tubular part 302 b areconnected along an axis of extension of the insulating tubular part 302or an axial direction of the light tube 1. The outer diameter of thesecond tubular part 302 b is less than the outer diameter of the firsttubular part 302 a. The outer diameter difference between the firsttubular part 302 a and the second tubular part 302 b is between 0.15 mmto 0.30 mm. The thermal conductive ring 303 is fixedly configured overand surrounding the outer circumferential surface of the second tubularpart 302 b. The outer surface of the thermal conductive ring 303 iscoplanar or substantially flush with respect to the outercircumferential surface of the first tubular part 302 a, in other words,the thermal conductive ring 303 and the first tubular part 302 a havesubstantially uniform exterior diameters from end to end. As a result,the end cap 3 achieves an outer appearance of smooth and substantiallyuniform tubular structure. In the embodiment, ratio of the length of thethermal conductive ring 303 along the axial direction of the end cap 3with respect to the axial length of the insulating tubular part 302 isfrom 1:2.5 to 1:5. In the present embodiment, the inner surface of thesecond tubular part 302 b and the inner surface of the thermalconductive ring 303, the outer surface of the rear end region 101 andthe outer surface of the transition region 103 together form anaccommodation space. In order to ensure bonding longevity using the hotmelt adhesive, in the present embodiment, the second tubular part 302 bis at least partially disposed around the light tube 1, the hot meltadhesive 6 is at least partially filled in an overlapped region (shownby a broken/dashed line identified as “A” in FIG. 7, also referredherein as “a second location”) between the inner surface of the secondtubular part 302 b and the outer surface of the rear end region 101 ofthe light tube 1, in which the second tubular part 302 b and the rearend region 101 of the light tube 1 are bonded by the hot melt adhesive 6disposed therebetween. During manufacturing of the LED tube light, whenthe hot melt adhesive 6 is coated and applied between the thermalconductive ring 303 and the rear end region 101, it may be appropriateto increase the amount of hot melt adhesive used, such that in thesubsequent heating process, the hot melt adhesive can be caused toexpand and flow in between the second tubular part 302 b and the rearend region 101, to thereby adhesively bond the second tubular part 302 band the rear end region 101. However, in the present embodiment, the hotmelt adhesive 6 does not need to completely fill the entireaccommodation space (as shown in the illustrated embodiment of FIG. 7),in which a gap is reserved or formed between the thermal conductive ring303 and the second tubular part 302 b. Thus, the hot melt adhesive 6 canbe only partially filing the accommodation space.

During fabrication of the LED tube light, the rear end region 101 of thelight tube 1 is inserted into one end of the end cap 3, the axial lengthof the portion of the rear end region 101 of the light tube 1 which hadbeen inserted into the end cap 3 accounts for one-third (⅓) totwo-thirds (⅔) of the total length of the thermal conductive ring 303 inan axial direction thereof. One benefit is that, the hollow conductivepins 301 and the thermal conductive ring 303 have sufficient creepagedistance therebetween, and thus is not easy to form a short circuitleading to dangerous electric shock to individuals. On the other hand,due to the insulating effect of the insulating tubular part 302, thusthe creepage distance between the hollow conductive pin 301 and thethermal conductive ring 303 is increased, and thus more people arelikely to obtain electric shock caused by operating and testing underhigh voltage conditions. In this embodiment, the insulating tube 302 ingeneral state, is not a good conductor of electricity and/or is not usedfor conducting purposes, but not limited to the use made of plastics,ceramics and other materials. Furthermore, for the hot melt adhesive 6disposed in the inner surface of the second tubular part 302 b, due topresence of the second tubular part 302 b interposed between the hotmelt adhesive 6 and the thermal conductive ring 303, therefore the heatconducted from the thermal conductive ring 303 to the hot melt adhesive6 may be reduced. Thus, referring to FIG. 5, in this another embodiment,the end of the second tubular part 302 b facing the light tube 1 (i.e.,away from the first tubular part 302 a) is provided a plurality ofnotches 302 c, configured for increasing the contact area of the thermalconductive ring 303 and the hot melt adhesive 6, in order to be moreconducive to provide rapid heat conduction from the thermal conductivering 303 to the hot melt adhesive 6, so as to accelerate the curing ofthe hot melt adhesive 6. The notches 302 c are spatially arranged alonga circumferential direction of the second tubular part 302 b. Meanwhile,when the user touches the thermal conductive ring 303, due to theinsulation property of the hot melt adhesive 6 located between thethermal conductive ring 303 and the light tube 1, no electrical shockwould likely be produced by touching damaged portion of the light tube1.

The thermal conductive ring 303 can be made of various heat conductingmaterials, the thermal conductive ring 303 of the present embodiment isa metal sheet, such as aluminum alloy. The thermal conductive ring 303being tubular or ring shaped is sleeved over the second tubular part 302b. The insulating tubular part 302 may be made of insulating material,but would have low thermal conductivity so as to prevent the heatconduction to reach the power supply components located inside the endcap 3, which then negatively affect performance of the power supplycomponents. In this embodiment, the insulating tubular part 302 is aplastic tube. In other embodiments, the thermal conductive ring 303 mayalso be formed by a plurality of metal plates arranged along a pluralityof second tubular part 302 b in either circumferentially-spaced or notcircumferentially-spaced arrangement. In other embodiments, the end capmay take on or have other structures. Referring to FIGS. 8-9, the endcap 3 according to another embodiment includes a magnetic object beingof a metal member 9 and an insulating tubular part 302, but not athermal conductive ring. The magnetic metal member 9 is fixedly arrangedon the inner circumferential surface of the insulating tubular part 302,and has overlapping portions with respect to the light tube 1 in theradial direction. The hot melt adhesive 6 is coated on the inner surfaceof the magnetic metal member 9 (the surface of the magnetic metal tubemember 9 facing the light tube 1), and bonding with the outer peripheralsurface of the light tube 1. In order to increase the adhesion area, andto improve the stability of the adhesion, the hot melt adhesive 6 cancover the entire inner surface of the magnetic metal member 9. Whenmanufacturing the LED tube light of the another embodiment, theinsulating tubular part 302 is inserted in an induction coil 11, so thatthe induction coil 11 and the magnetic metal member 9 are disposedopposite (or adjacent) to one another along the radial extendingdirection of the insulating tubular part 302. A method for bonding theend cap 3 and the light tube 1 with the magnetic metal member 9according to a second embodiment include the following steps. Theinduction coil 11 is energized. After the induction coil 11 isenergized, the induction coil 11 forms an electromagnetic field, and theelectromagnetic field upon contacting the magnetic metal member 9 thentransform into an electrical current, so that the magnetic metal member9 becomes heated. Then, the heat from the magnetic metal member 9 istransferred to the hot melt adhesive 6, thus curing the hot meltadhesive 6 so as to bond the end cap 3 with the light tube 1. Theinduction coil 11 and the insulating tubular part 302 are coaxiallyaligned, so that the energy transfer is more uniform. In thisembodiment, a deviation value between the axes of the induction coil 11and the insulating tubular part 302 is not more than 0.05 mm. When thebonding process is complete, the induction coil 11 is removed away fromthe light tube 1. The insulating tubular part 302 is further divide intotwo portions, namely a first tubular part 302 d and a second tubularpart 302 e. In order to provide better support of the magnetic metalmember 9, an inner diameter of the first tubular part 302 d at the innercircumferential surface of the insulating tubular part 302, forsupporting the magnetic metal member 9, is larger than the insidediameter of the second tubular part 302 e, and a stepped structure isformed by the insulating tubular part 302 and the second tubular part302 e, where an end of the magnetic metal member 9 as viewed in an axialdirection is abutted against the stepped structure. An inside diameterof the magnetic metal member 9 is larger than an outer diameter of theend (which is the rear end region 101) of the light tube 2. Uponinstallation of the magnetic metal member 9, the entire inner surface ofthe end cap 3 is maintained flush. Additionally, the magnetic metalmember 9 may be of various shapes, e.g., a sheet-like or tubular-likestructures being circumferentially arranged or the like, where themagnetic metal member 9 is coaxially arranged with the insulatingtubular part 302. In other embodiments, the manufacturing process forbonding the end cap 3 and the light tube 1 can be achieved without themagnetic metal member 9. The magnetic object such as iron power, nickelpower or iron-nickel power is directly doping into the hot melt adhesive6. When manufacturing the LED tube light 1 of the embodiment, the hotmelt adhesive 6 is filled between the inner circumferential surface ofthe insulating tubular part 32 of the end cap 3 and the end of the lighttube 1. After the induction coil 11 is energized, the induction coil 11forms an electromagnetic field, and the charged particles of themagnetic object become heated. Then, the heat generated from the chargedparticles of the magnetic object is transferred to the hot melt adhesive6, thus curing the hot melt adhesive 6 so as to bond the end cap 3 withthe light tube 1.

In other embodiments, the end cap 3 can also be made of all-metal, whichrequires to further provide an insulating member beneath the hollowconductive pins as safety feature for accommodating high voltage usage.

In other embodiments, the magnetic metal member 9 can have at least oneopening 901 as shown in FIG. 19, in which the openings 901 can becircular, but not limited to being circular in shape, such as, forexample, oval, square, star shaped, etc., as long as being possible toreduce the contact area between the magnetic metal member 9 and theinner peripheral surface of the insulating tubular part 302, but whilemaintaining the function of melting and curing the hot melt adhesive 6.Preferably, the openings 901 occupy 10% to 50% of the area of themagnetic metal member 9. The opening 901 can be arrangedcircumferentially around the magnetic metal member 9 in an equidistantlyspaced or not equally spaced manner. In other embodiments, the magneticmetal member 9 has an indentation/embossed structure 903 as shown inFIG. 20, in which the embossed structure 903 are formed to be protrudingfrom the inner surface of the magnetic metal member 9 toward the outersurface of the magnetic metal member 9, or vice versa, so long as thecontact area between the inner peripheral surface of the insulatingtubular part 302 and the outer surface of the magnetic metal member 9 isreduced, but can sustain the function of melting and curing the hot meltadhesive 6. In other embodiments, the magnetic metal member 9 is anon-circular ring, such as, but not limited to an oval ring as shown inFIG. 21. When the light tube 1 and the end cap 3 are both circular, theminor axis of the oval ring shape is slightly larger than the outerdiameter of the end region of the light tube 1, so long as the contactarea of the inner peripheral surface of the insulating tubular part 302and the outer surface of the magnetic metal member 9 is reduced, but canachieve or maintain the function of melting and curing the hot meltadhesive 6. When the light tube 1 and the end cap 3 is circular,non-circular rings can reduce the contact area between the magneticmetal member 9 and the inner peripheral surface of the insulatingtubular part, but still can maintain the function of melting and curinghot melt adhesive 6. In other words, the inner surface of the insulatingtubular part 302 includes a supporting portion 313, which supports the(non-circular shaped) magnetic metal member 9, so that the contact areabetween the magnetic metal member 9 and the inner surface of theinsulating tubular part 302 is reduced, but still achieve the meltingand curing of the hot melt adhesive 6. In other embodiments, the innercircumferential surface of the insulating tubular part 302 has aplurality of supporting portions 313 and a plurality of protrudingportions 310, as shown in FIGS. 16-18, in which the thickness of theprotruding portion 310 is smaller than the thickness of the supportingportion 313. A stepped structure is formed at an upper edge of thesupporting portion 313, in which the magnetic metal member 9 is abuttedagainst the upper edges of the supporting portions 313, so that themagnetic metal member 9 can be then securely or firmly mounted withinthe insulating tubular part 302. At least a portion of the protrudingportion 310 is positioned between the inner peripheral surface of theinsulating tubular part 302 and the magnetic metal member 9. Thearrangement of the protruding portions 310 may be in the circumferentialdirection of the insulating tubular part 302 at equidistantly spaced ornon-equidistantly spaced distances, the contact area of the innerperipheral surface of the insulating tubular part 302 and the outersurface of the magnetic metal member 9 is reduced, but can achieve ormaintain the function of melting and curing the hot melt adhesive 6. Theprotruding thickness of the supporting portion 313 toward the interiorof the insulating tubular part 302 is between 1 mm to 2 mm. Thethickness of the protruding portion 310 of the insulating tubular part302 that is disposed on the inner surface of the magnetic metal member 9is less than the thickness of the supporting portion 313, and thethickness of the protruding portion 310 is between 0.2 mm to 1 mm.

Referring again to FIG. 2, the LED tube light according to theembodiment of present invention also includes an adhesive 4, aninsulation adhesive 7, and an optical adhesive 8. The LED light bar 2 isbonded onto the inner circumferential surface of the light tube 1 byusing the adhesive 4. In the illustrated embodiment, the adhesive 4 maybe silicone adhesive, but is not limited thereto. The insulationadhesive 7 is coated on the surface of the LED light bar 2 facing theLED light sources 202, so that the LED light bar 2 is not exposed, thusinsulating the LED light bar 2 and the outside environment. Duringapplication of the adhesive, a plurality of through holes 701 arereserved and set aside corresponding to the positions/locations of theLED light sources 202. The LED light sources 202 are mounted in thethrough holes 701. The material composition of the insulation adhesive 7comprises vinyl silicone, hydrogen polysiloxane and aluminum oxide. Theinsulation adhesive 7 has a thickness range of 100 μm to 140 μm(microns). If less than 100 μm in thickness, the insulation adhesive 7will not achieve sufficient insulating effect, but if more than 140 μmin thickness, the excessive insulation adhesive will result in materialwaste. An optical adhesive 8 is applied or coated on the surface of theLED light source 202. The optical adhesive 8 is a clear or transparentmaterial, in order to ensure optimal light transmission rate. Afterproviding coating application to the LED light sources 202, the shape orstructure of the optical adhesive 8 may be in the form of a particulategel or granular, a strip or a sheet. A preferred range for therefractive index of the optical adhesive 8 is between 1.22 and 1.6.Another embodiment of the optical adhesive 8 can have a refractive indexvalue that is equal to a square root of the refractive index of thehousing or casing of the LED light source 202, or equal to plus or minus15% of the square root of the refractive index of the housing or casingof the LED light source 202, so as to achieve better lighttransmittance. The housing/casing of the LED light sources 202 is ahousing structure to accommodate and carry the LED dies (or chips) suchas a LED leadframe 202 b as shown in FIG. 15. The refractive index rangeof the optical adhesive 8 in this embodiment is between 1.225 and 1.253.The thickness of the optical adhesive 8 can be in the range of 1.1 mm to1.3 mm. When assembling the LED light sources to the LED light bar, theoptical adhesive 8 is applied on the LED light sources 202; then theinsulation adhesive 7 is coated on one side of the LED light bar 2. Thenthe LED light sources 202 are fixed or mounted on the LED light bar 2.The another side of the LED light bar 2 which is opposite to the side ofwhich the LED light sources 202 are mounted thereon, is bonded andaffixed using the adhesive 4 to the inner surface of the light tube 1.Later, the end cap 3 is fixed to the end portion of the light tube 1,while the LED light sources 202 and the power supply 5 are electricallyconnected by the LED light bar 2. Alternatively, as shown in FIG. 10,the LED light bar 2 can be used to pass through the transition region103 for providing electrical coupling to the power supply 5, ortraditional wire bonding methods can be adopted to provide theelectrical coupling as well. A finished LED tube light is thenfabricated upon the attachment or joining of the end caps 3 to the lighttube 1 as shown in FIG. 7 (with the structures shown in FIGS. 4-5), oras shown in FIG. 8 (with the structure of FIG. 9).

In the embodiment, the LED light bar 2 is fixed by the adhesive 4 to aninner circumferential surface of the light tube 1, so that the LED lightsources 202 are mounted in the inner circumferential surface of thelight tube 1, which can increase the illumination angle of the LED lightsources 202, thereby expanding the viewing angle, so that an excess of330 degrees viewing angle is possible to achieve. Through theutilization of applying the insulation adhesive 7 on the LED light bar 2and applying of the optical adhesive 8 on the LED light sources, theelectrical insulation of the LED light bar 2 is provided, so that evenwhen the light tube 1 is broken, electrical shock does not occur,thereby improving safety.

Furthermore, the LED light bar 2 may be a flexible substrate, analuminum plate or strip, or a FR4 board, in an alternative embodiment.Since the light tube 1 of the embodiment is a glass tube. If the LEDlight bar 2 adopts rigid aluminum plate or FR4 board, when the lighttube has been rupture, e.g., broken into two parts, the entire lighttube is still able to maintain a straight pipe or tube configuration,then the user may be under a false impression the LED tube light canremain usable and fully functional and easy to cause electric shock uponhandling or installation thereof. Because of added flexibility andbendability of the flexible substrate for the LED light bar 2, theproblem faced by the aluminum plate, FR4 board, conventional 3-layeredflexible board having inadequate flexibility and bendability are therebysolved. Due to the adopting of the flexible substrate/bendable circuitboard for the LED light bar 2 of present embodiment, the LED light bar 2allows a ruptured or broken light tube not to be able to maintain astraight pipe or tube configuration so as to better inform the user thatthe LED tube light is rendered unusable so as to avoid potentialelectric shock accidents from occurring. The following are furtherdescription of the flexible substrate/bendable circuit board used as theLED light bar 2. The flexible substrate/bendable circuit board and theoutput terminal of the power supply 5 can be connected by wire bonding,the male plug 501 and the female plug 201, or connected by solderingjoint. The method for securing the LED light bar 2 is same as before,one side of the flexible substrate is bonded to the inner surface of thelight tube 1 by using the adhesive 4, and the two ends of the flexiblesubstrate/bendable circuit board can be either bonded (fixed) or notbonded to the inner surface of the light tube 1. If the two ends of theflexible substrate are not bonded or fixed to the inner surface of thelight tube, and also if the wire bonding is used, the bonding wires areprone to be possibly broken apart due to sporadic motions caused bysubsequent transport activities as well as being freely to move at thetwo ends of the flexible substrate/bendable circuit board. Therefore, abetter option may be by soldering for forming solder joints between theflexible substrate and the power supply. Referring to FIG. 10, the LEDlight bar 2 in the form of the bendable circuit board can be used topass through the transition region 103 and soldering bonded to theoutput terminal of the power supply 5 for providing electrical couplingto the power supply 5, so as to avoid the usage of wire bonding, andimproving upon the reliability thereof. In the illustrated embodiment,the LED light bar 2 is not fixed to an inner circumferential surface ofthe light tube at two ends thereof. The flexible substrate does not needto have the female plug 201, and the output terminal of the power supply5 does not need to have the male plug 501. The output terminal of thepower supply 5 can have pads a, and leaving behind an amount of tinsolder on the pads a, so that the thickness of the tin solder on thepads a are sufficient enough for later forming a solder joint. Likewise,the ends of the bendable circuit board can also have pads b, so that thepads a from the output terminal of the power supply 5 are soldered tothe pads b of the bendable circuit board. In this embodiment, the pads bof the bendable circuit board are two separated pads for electricallyconnecting with the anode and the cathode of the bendable circuit board,respectively. In other embodiments, for the sake of achievingscalability and compatibility, the number or quantity of the pads b canbe more than two, for example, three, four, or more than four. When thenumber of pads are three, the third pad can be used for ground pad. Whenthe number of the pads are four, the fourth pad can be used for thesignal input terminal. Correspondingly, the pads a and the pads bpossess the same number of bond pads. When the number of bond pads is atleast three, the bond pads can be arranged in a row or two rows, inaccordance with dimensions of actual occupying area, so as to preventfrom being too close causing electrical short. In other embodiments, aportion of a printed circuit of the LED light bar can be configured onthe bendable printed circuit board, the pad b can be a single bond pad.The lesser the number of the bond pads, the more easier the fabricationprocess is to become. On the other hand, the more number of the bondpads, the bendable circuit board and the output terminal of the powersupply 5 have stronger and more secured electrical connectiontherebetween. In other embodiments, the inner portion of the bond pad ofthe pad b can have a plurality of through holes, the pad a can besoldered to the pad b, so that upon soldering, the solder tin canpenetrate through the through holes of the pad b. Upon exiting thethrough holes, the solder tin can be accumulated surrounding the outerperiphery of the opening of the through holes, so that upon cooling, aplurality of solder balls, with diameter larger than the diameter of thethrough holes, are formed. The solder balls possess similar function asnails, so that apart from having the solder tin to secure the pad a andthe pad b, the solder balls further act to strengthen the electricalconnection of the two pads a, b. In other embodiments, the through holesof the bond pads are disposed at the periphery, that is to say, the bondpad possess a notch, the pad a and the pad b are securely electricallyconnected via the solder tin extending and filling through the notch,and the excess solder tin would accumulate around the periphery of theopenings of the through holes, so that upon cooling, the solder ballswith diameter larger than the diameter of the through holes are formed,In the present embodiment, due to the notch structure of the bond pad,the solder tin has the function similar to C-shaped nails. Regardless ofwhether of forming the through holes of the bond pads before the solderbonding process or during the solder bonding process using the solderingtip directly, the same through holes structure of present embodiment canbe formed. The soldering tip and a contacting surface of the solder tincan be a flat, concaved, or convex surface, the convex surface can be along strip shape or of a grid shape. The convex surface of the soldertin does not completely cover the through holes of the bond pads, so asto ensure that the solder tin can penetrate through the through holes.When the solder tin has accumulated around the periphery of the openingof the through holes, the concaved surface can provide a receiving spacefor the solder ball. In other embodiments, the bendable circuit boardhas a tooling hole, which can be used to ensure precise positioning ofthe pad a with respect to the pad b during solder bonding. In the aboveembodiment, most of the bendable circuit board is attached and securedto the inner surface of the light tube 1. However, the two ends of thebendable circuit board are not secured or fixed to the inner surface ofthe light tube 1, which thereby form a freely extending end portion,respectively. Upon assembling of the LED tube light, the freelyextending end portion along with the soldered connection between theoutput terminal of the power supply and itself would be coiled, curledup or deformed to be fittingly accommodating inside the light tube 1, sothat the freely extending end portions of the bendable circuit board aredeformed in shape due to being contracted or curled to fit oraccommodate inside the light tube 1. Using the abovementioned bendablecircuit board of having the bond pad with through holes, the pad a ofthe power supply share the same surface with one of the surfaces of thebendable circuit board that is mounted with the LED light source. Whenthe freely extending end portions of the bendable circuit board aredeformed due to contraction or curling up, a lateral tension is exertedon the power supply at the connection end of the power supply and thebendable circuit board. In contrast to the solder bonding technique ofhaving the pad a of the power supply being of different surface to oneof the surfaces of the bendable circuit board that is mounted with theLED light source thereon, a downward tension is exerted on the powersupply at the connection end of the power supply and the bendablecircuit board, so that the bendable circuit board, with the through-holeconfigured bond pad, form a stronger and more secure electricalconnection between the bendable circuit board and the power supply. Ifthe two ends of the bendable circuit board are to be securely fixed tothe inner surface of the light tube 1, the female plug 201 is mounted onthe bendable circuit board, and the male plug 501 of the power supply 5is inserted into the female plug 201, in that order, so as to establishelectrical connection therebetween. Direct current (DC) signals arecarried on the conductive layer 2 a of the bendable circuit board,unlike the 3-layered conventional flexible substrates for carrying highfrequency signals using a dielectric layer. One of the advantage ofusing the bendable circuit board as shown in illustrated embodiment ofFIG. 10 over conventional rigid LED light bar is that damages orbreakages occurring during the wire bonding of the LED light bar and thepower supply through the narrowed curved region of the light tube (forconventional rigid LED light bar) is prevented by solder bonding of thebendable circuit board and then coiled back into the light tube toarrive at proper position inside the light tube.

Referring to illustrated embodiment of FIG. 11, the LED light bar 2 is abendable circuit board which includes a conductive layer 2 a and adielectric layer 2 b that are stackingly arranged. The LED light source202 is disposed on a surface of the conductive layer 2 a away from thedielectric layer 2 b. In other words, the dielectric layer 2 b isdisposed on the conductive layer 2 a away from the LED light sources202. The conductive layer 2 a is electrically connected to the powersupply 5. Meanwhile, the adhesive 4 is disposed on a surface of thedielectric layer 2 b away from the conductive layer 2 a to bond and tofix the dielectric layer 2 b to the inner circumferential surface of thelight tube 1. The conductive layer 2 a can be a metal layer serving as apower supply layer, or can be bonding wires such as copper wire. Inalternative embodiment, the LED light bar 2 further includes a circuitprotection layer (not shown). In another alternative embodiment, thedielectric layer can be omitted, in which the conductive layer isdirectly bonded to the inner circumferential surface of the light tube.The circuit protection layer can be an ink material, possessingfunctions as solder resist and optical reflectance. Whether theconductive layer 2 a is of one-layered, or two-layered structure, thecircuit protective layer can be adopted. The circuit protection layercan be disposed on the side/surface of the LED light bar 2, such as thesame surface of the conductive layer which has the LED light source 202disposed thereon. It should be noted that, in the present embodiment,the bendable circuit board is a one-layered structure made of just onelayer of the conductive layer 2 a, or a two-layered structure (made ofone layer of the conductive layer 2 a and one layer of the dielectriclayer 2 b), and thus would be more bendable or flexible to curl than theconventional three-layered flexible substrate. As a result, the bendablecircuit board (the LED light bar 2) of the present embodiment can beinstalled in other light tube that is of a customized shape ornon-linear shape, and the bendable circuit board can be mounted touchingthe sidewall of the light tube. The bendable circuit board mountedclosely to the tube wall is one preferred configuration, and the fewernumber of layers thereof, the better the heat dissipation effect, andthe lower the material cost. Of course, the bendable circuit board isnot limited to being one-layered or two-layered structure only, while inother embodiment, the bendable circuit board can include multiple layersof the conductive layers 2 a and multiple layers of the dielectriclayers 2 b, in which the dielectric layers 2 b and the conductive layers2 a are sequentially stacked in a staggered manner, respectively, to bedisposed on the surface of the one conductive layer 2 a that is oppositefrom the surface of the one conductive layer 2 a which has the LED lightsource 202 disposed thereon. The LED light source 202 is disposed on theuppermost layer of the conductive layers 2 a, and is electricallyconnected to the power supply 5 through the (uppermost) conductive layer2 a. Furthermore, the inner peripheral surface of the light tube 1 orthe outer circumferential surface thereof is covered with an adhesivefilm (not shown), for the sake of isolating the inner content fromoutside content of the light tube 1 after the light tube 1 has beenruptured. The present embodiment has the adhesive film coated on theinner peripheral surface of the light tube 1.

In a preferred embodiment, the light tube 1 can be a glass tube with acoated adhesive film on the inner wall thereof (not shown). The coatedadhesive film also serves to isolate and segregate the inside and theoutside contents of the light tube 1 upon being ruptured thereof. Thecoated adhesive film material includes methyl vinyl silicone oil, hydrosilicone oil, Xylene, and calcium carbonate The methyl vinyl siliconeoil chemical formula is: (C₂H₈OSi)n.C₂H₃. The hydrosilicon oil chemicalformula is: C₃H₉OSi.(CH₄OSi)n.C₃H₉Si; and the product produced ispolydimethylsiloxane (silicone elastomer), which has chemical formula asfollow:

Xylene is used as an auxiliary material. Upon solidifying or hardeningof the coated adhesive film when coated on the inner surface of thelight tube 1, the xylene will be volatilized and removed. The xylene ismainly used for the purpose of adjusting the degree of adhesion oradhesiveness, which can then adjust the thickness of the bondingadhesive thickness. In the present embodiment, the thickness of thecoated adhesive film can be between 10 to 800 microns (μm), and thepreferred thickness of the coated adhesive film can be between 100 to140 microns (μm). This is because the bonding adhesive thickness beingless than 100 microns, does not have sufficient shatterproof capabilityfor the glass tube, and thus the glass tube is prone to crack orshatter. At above 140 microns of bonding adhesive thickness would reducethe light transmittance rate, and also increase material cost. Vinylsilicone oil+hydrosilicone oil allowable ratio range is(19.8-20.2):(20.2-20.6), but if exceeding this allowable ratio range,would thereby negatively affect the adhesiveness or bonding strength.The allowable ratio range for the xylene and calcium carbonate is(2-6):(2-6), and if lesser than the lowest ratio, the lighttransmittance of the light tube will be increased, but grainy spotswould be produced or resulted from illumination of the LED light tube,negatively affect illumination quality and effect.

If the LED light bar 2 is configured to be a flexible substrate, nocoated adhesive film is thereby required.

To improve the illumination efficiency of the LED tube light, the lighttube 1 has been modified according to a first embodiment of presentinvention by having a diffusion film layer 13 coated and bonded to theinner wall thereof as shown in FIG. 12, so that the light outputted oremitted from the LED light sources 202 is transmitted through thediffusion film layer 13 and then through the light tube 1. The diffusionfilm layer 13 allows for improved illumination distribution uniformityof the light outputted by the LED light sources 202. The diffusion filmlayer 13 can be coated onto different locations, such as onto the innerwall or outer wall of the light tube 1 or onto the diffusion coatinglayer (not shown) at the surface of each LED light source 202, or coatedonto a separate membrane cover covering the LED light source 202. Thediffusion film layer 13 in the illustrated embodiment of FIG. 12 is adiffusion film that is not in contact with the LED light source 202 (butcovering above or over to enshrouding the LED light sources underneaththereof). The diffusion film layer 13 can be an optical diffusion filmor sheet, usually made of polystyrene (PS), polymethyl methacrylate(PMMA), polyethylene terephthalate (PET), and/or polycarbonate (PET), inone composite material composition thereof. In alternative embodiment,the diffusion film layer can be an optical diffusion coating, which hasa material composition to include at least one of calcium carbonate,halogen calcium phosphate and aluminum hydroxide that possessesexcellent light diffusion and transmittance to exceed 90%. Further, theapplying of the diffusion film layer made of optical diffusion coatingmaterial to outer surface of the rear end region 101 along with the hotmelt adhesive 6 would produce or generate increased friction resistancebetween the end cap and the light tube due to the presence of theoptical diffusion coating (when compared to that of an example that iswithout any optical diffusion coating), which is beneficial forpreventing accidental detachment of the end cap from the light tube.Composition of the diffusion film layer made by the optical diffusioncoating for the alternative embodiment includes calcium carbonate (e.g.,CMS-5000, white powder), thickening agents (e.g., thickeners DV-961,milky white liquid), and a ceramic activated carbon (e.g., ceramicactivated carbon SW-C, which is a colorless liquid). Wherein, thechemical name for the thickener DV-961 is colloidal silica modifiedacrylic acid resin used for enhancing calcium carbonate to be adhered tothe inner surface of the glass light tube 1, whose components includeacrylic acid resins, silicone and deionized water; ceramic activatedcarbon SW-C components include Sodium Di(2-ethylhexyl) Sulfosuccinate,isopropanol and deionized water, wherein the Sodium Di(2-ethylhexyl)Sulfosuccinate has the chemical formula as follow:

Specifically, average thickness of the diffusion film layer or theoptical diffusion coating falls between 20˜30 μm after being coated onthe inner circumferential surface of the glass tube, where finally thedeionized water will be evaporated, leaving behind the calciumcarbonate, ceramic activated carbon and the thickener. Using thisoptical diffusion coating material for forming the diffusion film layer13, a light transmittance of about 90% can be achieved. In addition,this diffusion film layer 13 can also provide electrical isolation forreducing risk of electric shock to a user upon breakage of the lighttube. Furthermore, the diffusion film layer 13 provides an improvedillumination distribution uniformity of the light outputted by the LEDlight sources 202 so as to avoid the formation of dark regions seeninside the illuminated or lit up light tube 1. In other embodiments, theoptical diffusion coating can also be made of strontium phosphate (or amixture of calcium carbonate and strontium phosphate) along with athickening agent, ceramic activated carbon and deionized water, and thecoating thickness can be same as that of present embodiment. In anotherpreferred embodiment, the optical diffusion coating material may becalcium carbonate-based material with a small amount of reflectivematerial (such as strontium phosphate or barium sulfate), the thickener,deionizes water and carbon activated ceramic to be coated onto the innercircumferential surface of the glass tube with the average thickness ofthe optical diffusion coating falls between 20˜30 μm. Then, finally thedeionized water will be evaporated, leaving behind the calciumcarbonate, the reflective material, ceramic activated carbon and thethickener. The diffusion phenomena in microscopic terms, light isreflected by particles. The particle size of the reflective materialsuch as strontium phosphate or barium sulfate will be much larger thanthe particle size of the calcium carbonate. Therefore, selecting a smallamount of reflective material in the optical diffusion coating caneffectively increase the diffusion effect of light. In otherembodiments, halogen calcium phosphate or aluminum hydroxide can also beserved as the main material for forming the diffusion film layer 13.

Furthermore, as shown in FIG. 12, the inner circumferential surface ofthe light tube 1 is also provided or bonded with a reflective film layer12, the reflective film layer 12 is provided around the LED lightsources 202, and occupy a portion of an area of the innercircumferential surface of the light tube 1 arranged along thecircumferential direction thereof. As shown in FIG. 12, the reflectivefilm layer 12 is disposed at two sides of the LED light sources 202extending along a circumferential direction of the light tube. Thereflective film layer 12 when viewed by a person looking at the lighttube from the side (in the X-direction shown in FIG. 12) serve to blockthe LED light sources 202, so that the person does not directly see theLED light sources 202, thereby reducing the visual graininess effect. Onthe other hand, reflection light passes through the reflective film 12emitted from the LED light source 202, can control the divergence angleof the LED tube light, so that more light is emitted in the directionthat has been coated with the reflective film, such that the LED tubelight has higher energy efficiency when providing same level ofillumination performance. Specifically, the reflection film layer 12provided on the inner peripheral surface of the light tube 1, and has aplurality of openings 12 a on the reflective film layer 12 which areconfigured corresponding to the locations of the LED light sources 202,the sizes of the openings 12 a are the same or slightly larger than thesize of the LED light source 202. During assembly, the LED light sources202 are mounted on the LED light bar 2 (or flexible substrate) providedon the inner surface of the light tube 1, and then the reflective filmlayer 12 is adhered to the inner surface of the light tube, so that theopenings 12 a of the reflective film layer 12 are matched to thecorresponding LED light sources 202 in a one-to-one relationship, andthe LED light sources 202 are exposed to the outside of the reflectivefilm layer 12. In the present embodiment, the reflectance of thereflective film layer 12 is at least greater than 85%. Betterreflectance of 90% can also be achieved. Meanwhile, more preferablyreflectance at more than 95% reflectance can also be achievable, inorder to obtain more reflectance. The reflective film layer 12 extendscircumferentially along the length of the light tube 1 occupying about30% to 50% of the inner surface area of the light tube 1. In otherwords, extending along a circumferential direction of the light tube 1,a circumferential length of the reflective film layer 12 along the innercircumferential surface of the light tube 1 and a circumferential lengthof the light tube 1 has a ratio of 0.3 to 0.5. In the illustratedembodiment of FIG. 12, the reflective film layer 12 is disposedsubstantially in the middle along a circumferential direction of thelight tube 1, so that the two distinct portions or sections of thereflective film layer 12 disposed on the two sides of the LED light bar2 are substantially equal in area. The reflective film layer 12 materialmay be made of PET or selectively adding some reflective materials suchas strontium phosphate or barium sulfate, with a thickness between 140μm to 350 μm, or between 150 μm to 220 μm for a more preferredembodiment. In other embodiments, the reflective film layer 12 may beprovided in other forms, for example, along the circumferentialdirection of the light tube 1 on one or both sides of the LED lightsource 202, while occupying the same 30% to 50% of the inner surfacearea of the light tube 1. Alternatively, as shown in FIG. 13, thereflective film layer 12 can be without any openings, so that thereflective film layer 12 is directly adhered or mounted to the innersurface of the light tube 1 as that of illustrated embodiment, andfollowed by mounting or fixing the LED light bar 2, with the LED lightsources 202 already being mounted thereon, on the reflective film layer12. In another embodiment, just the reflection film layer 12 may beprovided without a diffusion film layer 13 being present, as shown inFIG. 14.

In another embodiment, the reflective film layer 12 and the LED lightbar 2 are contacted on one side thereof as shown in FIG. 22. Inaddition, a diffusion film layer 13 is disposed above the LED light bar2. Referring to FIG. 23, the LED light bar 2 (with the LED light sources202 mounted thereon) is directly disposed on the reflective film layer12, and the LED light bar 2 is disposed at an end region of thereflective layer 12 (without having any diffusion layer) of the LED tubelight of yet another embodiment of present invention.

In other embodiments, the width of the LED light bar 2 (along thecircumferential direction of the light tube) can be widened to occupy acircumference area of the inner circumferential surface of the lighttube 1 at a ratio between 0.3 to 0.5, in which the widened portion ofthe LED light bar 2 can provide reflective effect similar to thereflective film. As described in the above embodiment, the LED light bar2 may be coated with a circuit protection layer, the circuit protectionlayer may be an ink material, providing an increased reflectivefunction, with a widened flexible substrate using the LED light sourcesas starting point to be circumferentially extending, so that the lightis more concentrated. In the present embodiment, the circuit protectionlayer is coated on just the top side of the LED light bar 2 (in otherwords, being disposed on an outermost layer of the LED light bar 2 (orbendable circuit board).

In the embodiment shown in FIGS. 12-14, the inner circumferentialsurface of the glass light tube, can be coated entirely or partiallywith an optical diffusion coating (parts that have the reflective filmbeing coated would not be coated by the optical diffusion coating). Theoptical diffusion coating is preferably applied to the outer surface atthe end region of the light tube 1, so that the end cap 3 and the lighttube 1 can be bonded more firmly.

Referring to FIG. 15, the LED light source 202 may be further modifiedto include a LED leadframe 202 b having a recess 202 a, and an LED chip18 disposed in the recess 202 a. The recess 202 a is filled withphosphor, the phosphor coating is covered on the LED chip 18 to convertto the desired color light. In one light tube 1, there are multiplenumber of LED light sources 202, which are arranged into one or morerows, each row of the LED light sources 202 is arranged along the axisdirection or length direction (Y-direction) of the light tube 1. Therecess 202 a belonging to each LED leadframe 202 b may be one or more.In the illustrated embodiment, each LED leadframe 202 b has one recess202 a, and correspondingly, the LED leadframe 202 b includes two firstsidewalls 15 arranged along a length direction (Y-direction) of thelight tube 1, and two second sidewalls 16 arranged along a widthdirection (X-direction) of the light tube 1. In the present embodiment,the first sidewall 15 is extending along the width direction(X-direction) of the light tube 1, the second sidewall 16 is extendingalong the length direction (Y-direction) of the light tube 1. The firstsidewall 15 is lower in height than the second sidewall 16. The recess202 a is enclosed by the first sidewalls 15 and the second sidewalls 16.In other embodiments, in one row of the LED light sources, it ispermissible to have one or more sidewalls of the LED leadframes of theLED light sources to adopt other configuration or manner of extensionstructures. When the user is viewing the along the X-direction towardthe light tube, the second sidewall 16 can block the line of sight ofthe user to the LED light source 202, thus reducing unappealing grainyspots. The first sidewall 15 can be extended along the width directionof the light tube 1, but as long as being extended along substantiallysimilar to the width direction to be considered sufficient enough, andwithout requiring to be exactly parallel to the width direction of thelight tube 1, and may be in a different structure such as zigzag,curved, wavy, and the like. The second sidewall 16 can be extended alongthe length direction of the light tube 1 but as long as being extendedalong substantially similar to the length direction to be consideredsufficient enough, and without requiring to be exactly parallel to thelength direction of the light tube 1, and may be in a differentstructure such as zigzag, curved, wavy, and the like. Having the firstsidewall 15 being of a lower height than the second sidewall 16 isbeneficial for allowing light illumination to easily dispersed beyondthe LED leadframe 202 b, and no grainy effect is produced upon viewingin the Y-direction. The first sidewall 15 includes an inner surface 15a. The inner surface 15 a of the first sidewall 15 is a sloped surface,which promotes better light guiding effect for illumination and facingtoward outside of the recess. The inner surface 15 a can be a flat orcurved surface. The slope of the inner surface 15 a is between about 30degrees to 60 degrees. In other words, the included angle between thebottom surface of the recess 202 a and the inner surface 15 a is between120 and 150 degrees. In other embodiments, the slope of the innersurface of the first sidewall can also be between about 15 degrees to 75degrees, that is, the included angle between the bottom surface of therecess 202 a and the inner surface of the first sidewall is between 105degrees to 165 degrees. Alternatively, the slope may be a combination offlat and curved surface. In other embodiments, if there are several rowsof the LED light sources 202, arranged in a length direction(Y-direction) of the light tube 1, as long as the LED leadframes 202 bof the LED light sources 202 disposed in the outermost two rows (atclosest to the light tube) along in the width direction of the lighttube 1, are to have two first sidewalls 15 configured along the lengthdirection (Y-direction) and two second sidewalls 16 configured in onestraight line along the width direction (X-direction), so that thesecond sidewalls 16 are disposed on a same side of the same row arecollinear to one another. However, the arrangement direction of the LEDleadframes 202 b of the other LED light sources 202 that are locatedbetween the aforementioned LED light sources 202 disposed in theoutermost two rows are not limited, for example, for the LED leadframes202 b of the LED light sources 202 located in the middle row (thirdrow), each LED leadframe 202 b can include two first sidewalls 15arranged along in the length direction (Y-direction) of the light tube1, and two second sidewalls 16 arranged along in the width direction(X-direction) of the light tube 1, or alternatively, each LED leadframe202 b can include two first sidewalls 15 arranged along in the widthdirection (X-direction) of the light tube 1, and two second sidewalls 16arranged along in the length direction (Y-direction) of the light tube1, or arranged in a staggered manner. When the user is viewing fromvantage point from the side of the light tube along the X-direction, theoutermost two rows of the LED leadframes 202 b of the LED light sources202 can block the user's line of sight for directly seeing the LED lightsources 202. As a result, the visual graininess unpleasing effect isreduced. Similar to the present embodiment, with regard to the twooutermost rows of the LED light sources, one or more of the sidewalls ofthe LED leadframes of the LED light sources to adopt otherconfigurational or distribution arrangement. When multiple number of theLED light sources 202 are distributed or arranged along the lengthdirection of the light tube in one row, the LED leadframes 202 b of themultiple number of the LED light sources 202 have all of the secondsidewalls 16 thereof disposed in one straight line along the widthdirection of the light tube, respectively, that is to say, being at thesame side, the second sidewalls 16 form substantially a wall structureto block the user's line or sight from seeing directly at the LED lightsource 202. When the multiple number of the LED light sources 202 aredistributed or arranged along the length direction of the light tube inmultiple rows, the multiple number of the LED light sources 202 aredistributed or arranged along the width direction, with regard to thetwo outermost rows of the LED light sources located along the widthdirection of the light tube, each row of the LED leadframes 202 b of themultiple number of the LED light sources 202, in which all of the secondsidewalls 16 disposed at the same side are in one straight line alongthe width direction of the light tube, that is to say, being at the sameside, as long as the second sidewalls 16 of the LED light sources 202located at the outermost two rows can block the user's line of sight fordirectly seeing the LED light sources 202, the reduction of visualgraininess unpleasing effect can thereby be achieved. Regarding the oneor more middle row(s) of the LED light sources 202, the arrangement,configuration or distribution of the sidewalls are not specificallylimited to any particular one, and can be same as or different from thearrangement and distribution of the two outermost rows of the LED lightsources, without departing from the spirit and scope of presentdisclosure.

In one embodiment, the LED light bar includes a dielectric layer and oneconductive layer, in which the dielectric layer and the conductive layerare arranged in a stacking manner.

The narrowly curved end regions of the glass tube can reside at twoends, or can be configured at just one end thereof in differentembodiments. In alternative embodiment, the LED tube light to furtherincludes a diffusion layer (not shown) and a reflective film layer 12,in which the diffusion layer is disposed above the LED light sources202, the light emitting from the LED light sources 202 is passed throughthe diffusion layer and the light tube 1. Furthermore, the diffusionfilm layer can be an optical diffusion covering above the LED lightsources without directly contacting thereof. In addition, the LED lightsources 202 can be bondedly attached to the inner circumferentialsurface of the light tube. In other embodiment, the magnetic metalmember 9 can be a magnetic object that is magnetic without being made ofmetal. The magnetic object can be doping into the hot melt adhesive.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not be limited to the disclosedembodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

1. An LED tube light, comprising: a plurality of LED light sources; anend cap; a light tube, having an end attached to the end cap; a powersupply, disposed in the end cap; and an LED light bar, disposed insidethe light tube, the LED light sources being mounted on the LED lightbar, the LED light sources and the power supply being electricallyconnected by the LED light bar; wherein the LED light bar issubstantially linearly configured and a bendable circuit board, thebendable circuit board is made of one conductive layer and onedielectric layer to form a two-layered structure, the dielectric layeris disposed on a surface of the conductive layer that is away from theLED light sources and fixed to an inner circumferential surface of thelight tube, the LED light sources are disposed on the conductive layerand are electrically connected to the power supply by the conductivelayer therebetween, the bendable circuit board forms a freely extendingend portion at two ends thereof, respectively, wherein the freelyextending end portion is an integral portion of the bendable circuitboard, upon breaking of the light tube, the broken light tube does notmaintain a straight tube configuration so that the LED tube light isstructurally rendered unusable.
 2. An LED tube light, comprising: aplurality of LED light sources; an end cap; a light tube, having an endattached to the end cap; a power supply, disposed in the end cap; and anLED light bar, disposed inside the light tube; wherein the LED light baris a bendable circuit board, the LED light sources are mounted on theLED light bar, and the LED light sources and the power supply areelectrically connected by the LED light bar, the bendable circuit boardforms a freely extending end portion at two ends thereof, respectively,wherein the freely extending end portion is an integral portion of thebendable circuit board.
 3. The LED tube light of claim 2, wherein theLED light bar comprises a conductive layer being of one layer, the LEDlight sources are disposed on the conductive layer and are electricallyconnected to the power supply by the conductive layer therebetween. 4.The LED tube light of claim 3, wherein the LED light bar furthercomprises a dielectric layer, the dielectric layer is disposed on theconductive layer away from the LED light sources, and fixed to an innercircumferential surface of the light tube.
 5. The LED tube light ofclaim 2, wherein the LED light bar further has one conductive layerbeing of only one metal layer, only one dielectric layer and a circuitprotection layer being of one layer disposed on the conductive layer,the dielectric layer is disposed on the conductive layer away from theLED light sources.
 6. The LED tube light of claim 2, wherein the LEDlight bar is extending along a circumferential direction of the lighttube, a circumferential length of the bendable circuit board along aninner circumferential surface of the light tube and a circumferentiallength of the inner circumferential surface of the light tube is at aratio of 0.3 to 0.5.
 7. The LED tube light of claim 4, wherein thebendable circuit board further comprises a circuit protection layerbeing of one layer disposed on an outermost layer of the conductivelayer of the bendable circuit board.
 8. The LED tube light of claim 4,wherein the bendable circuit board further comprises a circuitprotection layer being of two layers respectively disposed on outermostlayers of the conductive layer and the dielectric layer of the bendablecircuit board.
 9. The LED tube light of claim 2, wherein the LED lightbar is substantially linearly configured, and two ends of the LED lightbar are not fixed to an inner circumferential surface of the light tube,respectively.
 10. The LED tube light of claim 9, wherein the freelyextending end portion is curled up, coiled or deformed in shape to befittingly accommodated inside the light tube.
 11. The LED tube light ofclaim 2, wherein an end of the bendable circuit board is directlysoldered to the power supply.
 12. The LED tube light of claim 2, whereinthe light tube including a main region and a plurality of rear endregions, each diameter of the rear end regions is less than a diameterof the main region thereof, the end cap is fittingly sleeved on the rearend region of the light tube.
 13. The LED tube light of claim 12,wherein the light tube further includes a transition region between themain region and the rear end regions.
 14. The LED tube light of claim13, wherein the bendable circuit board is passed through the transitionregion to be electrically connected to the power supply.
 15. The LEDtube light of claim 14, wherein the bendable circuit board is directlysoldered to the power supply.
 16. The LED tube light of claim 13,wherein each of the transition regions has a length of 1 mm to 4 mm. 17.The LED tube light of claim 2, further comprising a reflective filmlayer, the reflective film layer is disposed on an inner circumferentialsurface of the light tube and occupying a portion of an area of theinner circumferential surface of the light tube.
 18. The LED tube lightof claim 17, wherein the bendable circuit board is disposed on thereflective film layer.
 19. The LED tube light of claim 17, wherein thebendable circuit board is disposed on one side of the reflective filmlayer.
 20. The LED tube light of claim 17, wherein a ratio of acircumferential length of the reflective film layer along the innercircumferential surface of the light tube and a circumferential lengthof the light tube is 0.3 to 0.5.
 21. The LED tube light of claim 2,wherein the bendable circuit board comprises a plurality of conductivelayers and a plurality of dielectric layers, the dielectric layers andthe conductive layers are sequentially and staggerly stacked,respectively, on a surface of one conductive layer that is opposite fromthe surface of another conductive layer having the LED light sourcedisposed thereon, the LED light source is disposed on an uppermost layerof the conductive layers, and is electrically connected to the powersupport by the uppermost layer of the conductive layers.
 22. An LED tubelight, comprising: a plurality of LED light sources; two end caps,having a power supply disposed therein; a light tube, having two endsrespectively attached to the two end caps; and an LED light bar,disposed inside the light tube, the LED light sources being mounted onthe LED light bar, the LED light sources and the power supply beingelectrically connected by the LED light bar; wherein the LED light baris a bendable circuit board, the bendable circuit board is made of aconductive layer and a dielectric layer, the dielectric layer isdisposed on the conductive layer away from the LED light sources, thebendable circuit board forms a freely extending end portion at two endsthereof, respectively, wherein the freely extending end portion is anintegral portion of the bendable circuit board, the LED light sourcesare disposed on the conductive layer and are electrically connected tothe power supply by the conductive layer therebetween; wherein each endof the bendable circuit board respectively has two separated pads forelectrically connecting to the power supply by soldering.
 23. The LEDlight tube of claim 22, wherein the conductive layer and the dielectriclayer form a two-layered structure for the bendable circuit board, thedielectric layer is disposed on a surface of the conductive layer thatis away from the LED light sources and fixed to an inner circumferentialsurface of the light tube.